The problem with information that you read on the Internet is that it is not always true. -- Abraham Lincoln, April 31, 1867
Satire: "the use of humor, irony, exaggeration, or ridicule to expose and criticize people's stupidity or vices, particularly in the context of contemporary politics and other topical issues." [definition from Google search]
Some websites may claim to be satire as a defense against potential legal action, but their content may often mislead readers into believing it is true.
It should be obvious when a site's stories are outrageous or intended to entertain through satire, such as the following sites: